Pivotally connected steerable and driven tractor units



March 30, 1954 u. A. MOORES PIVOTALLY CONNECTED STEERABLE AND DRIVENTRACTOR UNITS Filed May 215, 1952 5 Sheets-Sheet 2 a w 2 3 3 a w w 3% 739/ 34 2 m 9 8 5 6 G H M w 5 4 4 O 3 w I m 1. 2 425 1 l 8 $3 3 3 F 5 I ll 6 7 a I 4 8 w 9 F 2 3 l B 4 6 5 M 4 B n F 7 a 2 5 l 0 H I 5 w |l| II 4l- 5 FIG. 9

INVENTOR URBAN A. MOORES ATTORNEY March 30, 1954 u. A. MOORES 2,673,616

PIVOTALLY CONNECTED STEERABLE AND DRIVEN TRACTOR UNITS Filed May 23,1952 5 Sheets-Sheet 3 Tn inn In ENTOR UR A. MOORES ATTORNEY PatentedMar. 30, 1954 UNITED STATES PATENT OFFICE PIVOTALLY CONNECTED STEERABLEAND DRIVEN TRACTOR UNITS Urban A.Moores', Rutland Heights, Mass.

Application May 23, 1952, Serial No. 289,465

6'Claims. 1.

This invention relates to tractors and'it is the general obect of theinvention to provide a dual tractor the two parts of which are pivotedtogether' around an axis shiftable laterally to effect steering andthrough which drving power is transmitted.

The coupling together of two tractor units both driven from a singleengine usually introduces difficulties of steering, since the two unitsmust be able to move angularly with respect to each other withoutdisturbing the transmission of driving power between the units. In orderto overcome this difficulty it is an important object of the presentinvention-to pivot the two units together around a vertical axis andtransmit power froma source of power on one unit to the other unitthrough mechanism having a, part which is coaxial with the pivot of theunits. Lateral movement of thispart of the mechanism while the units arebeing driven can then be effected to change the angular relation of theunits for steering purposes It is a further'object of the inventiontojoin thetwo units by a lengthwise support means or member the endsofwhich are provided with pivots, one for each unit, and theintermediatepart of which supports means to shift and guide theaforesaidaxislaterally with respect to a line joining the pivots oftheunits.

It is a further object of the invention to effect lateral shifting ofthe vertical axisby a motor connectedto mechanism which when operated bythe motor causes the previously mentioned lateral shift ofthe verticalaxis. The motor is preferably used with heavy duty tractor units themanual steering of which would be difficult. The motor may convenientlybe mounted on the aforesaid support member and operate a transversescrew the turning of which under the control of the driver moves theaforesaid part of the power transmitting system.

A further object of the invention relates to a modified form adaptableto lighter duty tractors and provides a manually operable pinion whichwhen turned by the drive rolls along a gear rack on the support memberto shift the part of the transmission mechanism rotatable about the axisabout which the two tractor units are pivoted.

Other objectswill appear as the invention is set forth in the followingdescription.

By way of examples two forms of the invention are shown in theaccompanying drawings, wherem:

Fig. 1 is a side elevation of a dual tractor made according to thepreferred form of the invention,

' 2-2 and 3-3, respectively, Fig. 1,

Fig. 4. is an enlarged vertical section on line l- Fig. 3,

Fig. 5 is an enlarged vertical section online 55, Fig. 2,

Fig. 6 is a vertical section-on line 6-6, Fig. 5;

Fig. 7 is a fragmentary verticalsectionon line 5.

Fig. 8 is an enlarged horizontal section on line 8-8, Fig. 1,

Fig. 9 is a vertical section on line 9-9,'Fig 8, showing parts of theendless tread drives for the two tractor units,

Fig. 10 is a diagrammatic plan showing the ractor in two differentpositions for steering in two difierent directions,

Fig. 11 is aside elevation of the modified form of the invention,

Fig. 12 is an enlarged horizontal section on line iz-il, Fig. 11,

Fig. 13 is an'enlarged vertical section on line |3l3, Fig. 11,

Fig. 14 is a detail vertical section on line 14-44; Fig. 12, and

Fig. 15 is a diagrammatic plan view showing the'two units of themodified tractor inposition to turn in one direction.

Referring to Figs. 1 and 2, the preferred form of the dual tractor '1comprises a front endless tread unit F on which is mounted a drivingmotor I, such as an internal combustion engine, and a rear endless treadunit R on which a-fuel tank 2 is mounted. A gear shift lever ofconventional form is shown at 3 and the engine has a driving shaft 4.The engine may be of usual design'and. a fuel feed line (not shown)connectingthe engine and tank will be constructed as to remain intactwhen the units turn with respect to each other, as will be described.

Unit F includes a horizontal chassis member 5 under the engine andhaving oppositely etxending front arms 6 secured thereto by bolts 1.Depending from the arms 6 are bearing members 3 for idler sprocketwheels 9 for an endless tread lag chain it. Tranverse lags H- formingpart of the linked endless tread-chain adapt the tractor unit for travelover soft terrain. Rear oppositely extending arms l2 are bolted at l3 tomember 5 and have depending bearing members M which support a transversechain driving shaft l5. Chain driving sprocket wheels 16 are secured toshaft i 5 and are the means by which the endless tread chain is driven.

Intermediate oppositely extending arms I! are bolted at l8 to chassismember 5 and have depending bearing members l9 one of which is shown inFig. 1. Unit supporting wheels 26 are journaled on member l9 and meshwith the endless tread chain 10 as will be apparent from Fi l.

The rear unit R is similar to unit F and has a horizontal chassis member2| under the tank 2 and has rear arms 22, front arms 23 and intermediatearms 24 similar, respectively, to arms 6, l2 and l! of unit F. A rearendless tread lag chain 25 is trained around idler sprocket wheels 26similar to wheels 9 and driving sprocket wheels 27 secured to chaindriving shaft 28 similar, respectively, to parts it and i5. Unit B hassupporting wheels 29 similar to wheels 26. The tank 2 is supported inany approved manner on the chassis member 2! and arms 24, and similarly,the engine is appropriately supported by chassis member 5 and arms H.

The two units F and R are pivotally connected as shown in Fig. 9. Thechassis member 5 is made with a pivot head formed with upper and lowerbearings 3i and 32, respectively, and the chassis member 2! has a pivothead 33 formed with an upper bearing 36 which fits closely betweenbearings 3| and 32. A lower bearing 35 on head fits under bearing 32 anda vertical tube or sleeve member 36 passing through bearings 55, 32, 3dand 35 serves to connect the units F and F, pivotally.

A support member or plate 66, see Figs. 2 and 3, has a centraltransverse part 0.! formed with a guide slot 62 extending verticallythrough said part and preferably at right angles to the length of theguide plate. A screw 53 is located in slot 42 and has its ends rotatablymounted in bearings 44 and 45 at opposite ends of the slot. The screw isfree to turn in these bearings but is held against endwise movement byshoulders 46 which engage the bearings 46 and 45. The lower end of tube36 is formed with a hub 6? through which screw 46 is threaded, see Fig.5.

As shown in Fig. 5 the left hand end of the screw member 63 has securedthereto a bevel gear 50 which meshes with a second bevel gear 5i securedto shaft 52 of an electric motor 53. Support plate 66 has a frame 56:fastened thereto at 55 and the motor 53 is mounted on this frame so thatthe motor is fixed with respect to the support plate. The electric motoris reversible and is controlled from a switch handle 56 shown in Fig. 1.The electric circuits for the motor are not shown, nor is the source ofelectric power to drive it, and it is thought sufficient to state thatthe usual storage battery and conventional wiring will enable the driveof the dual tractor to cause the motor 53 to turn in either direction orbe at rest.

Opposite sides of hub 41'! are preferably grooved at 5'! to receiveguide rods 58 extending along slot 42 and fastened to the under side ofsupport plate by screws 59, see Fig. 6. The left end of the supportplate as shown in Fig. 3 has a short straight slot 66 therein whichreceives a king pin bolt 6! the upper end of which is tapped intochassis member 5 and held by nut 62, see Fig. 4. The king pin has acylindrical bearing part 63 fitting the slot 66 and a head 6 which holdsthe guide plate closely against the under side of the chassis member.Two other bolts 65 and 66 similar to the king pin extend through arcuateslots 0! and 68, respectively, in lateral arms 69 on chassis member 5.These bolts are tapped into the oppositely extending arms ll. Theopposite end of support 40 is similar to the left end, Fig. 3,

4 and has bolts 16 similar to bolts GI, 65 and 66. The parts justdescribed permit the units F and R to move angularly in a horizontalplane with respect to the support plate 40 when the tube 36 is moved dueto turning of screw 43 by motor 53.

Power is transmitted from the engine I to the endless tread chaindriving sprockets by the mechanism shown in Figs. 8 and 9. The enginedrive shaft 4 has secured thereto a worm H meshing with a worm gear 72secured to a cross shaft 73 rotatable on a bearing block 54 fastened atto the chassis member 5 and its head 30. Chain sprockets 16 secured tothe ends of shaft 33 mesh with chains if, one of which is shown in Fig.9, which in turn drive sprockets 78 secured to the ends of shaft 5. Thetrain Ii-18 thus provides driving means for the lag chain of the frontunit F.

A mitre gear 80 secured to shaft 4 meshes with a second mitre gear 8|pinned to the bottom of a short vertical shaft 82 rotatable in bearingblock 14 and having another mitre gear 83 secured to the upper endthereof. Gear 83 meshes with a mitre gear 84 secured to a shorthorizontal shaft 85 rotatable in bearing block 1 and having a mitre gear86 secured to the right end thereof, see Fig. 9.

A vertical driving shaft 81 rotates within the tube or sleeve 36 as alower bearing and has an upper bearing 88 secured at 89 to a stand 90fastened at 6| to the rear chassis member 2|. Shaft 81 is thereforerotatable about the vertical axis along which the units F and R arepivoted together. Shaft 87 has secured thereto a double mitre gear 92the upper part of which meshes with gear 86 and the lower part of whichmeshes with mitre gear 93 pinned to a horizontal worm shaft G lrotatable in a bearing housing 95 secured at 96 to pivot head 33. Shaft94 has a worm 96 meshing with a worm wheel 91 secured to a short crossshaft 98 turning in bearing 95. Sprocket wheels 99 on shaft 98 driveshort chains I00 which in turn drive sprockets IOI on a cross shaft I62rotatable in bearing members [4 on arms 23. Chains I03 meshing withsprockets IOI and sprockets I04 secured to shaft 28 convey driving forceto the lag chain for the rear unit R.

From the matter thus far described it will be understood that when theunits F and R are aligned with the tube 36 and vertical shaft 81substantially centrally located with respect to slot 42, as suggested inFig. 2, the dual tractor will move straight ahead. If the driver wishesto turn to the left when traveling in the direction of arrow a, Fig. 10,he will move switch handle 56 in a direction to cause the motor 53 toturn screw 63 in such a direction as will move the sleeve 36 and shaft81 to the right end of slot 42 and the units F and R will then be in therelative position shown in full lines, Fig. 10. If a right hand turn isdesired the motor 53 will be caused to turn in the opposite directionand the units will then be as indicated in dotted lines, Fig. 10. Theturning can be regulated by the length of time the electric motor isrunning as determined by the operator manipulating switch handle 56.During turning of the dual tractor power is transmitted through doublemitre gear 92 to the lag chain of the rear unit R.

In the modified form of the invention shown in Figs. l1-15 the two unitsare mounted on wheels and the steering is effected by moving thevertical axis of the power transmission mechanism by manually operatedmeans.

magma- H3 and H4, respectively, the rear endsof which are provided withvertically aligned'bearings II5 and'IIS, respectively. These bearingsare of the split type and include rear cap'bea'ring members The sourceof power, as-engine I similar to engine 2; issupported by differentialmechanism H2 and .upper chassis member H3 and has a driving. shaft I2I,a gear shift lever I22, and a clutch lever I23, all of usualconstruction.

The rear unit RI has wheels I25 driven by a differential mechanism I26to which are secured forwardly extending upper and lower chassismembersl21 and H8, respectively. Member I21 has a bearing I30 below andvertically aligned with bearing I I5. Bearing I is also of the splittype and has a cap member I3I. The lower chassis member l28has a bearingI32 below and vertically aligned with bearing H6 and provided with a capbearing-member I33. A fuel tank I54 is mounted on the differentialmechanism I26.

The engine driving shaft I2I has secured thereto a mitre gear I35meshing with a mitre gear I 35 secured'to a short vertical shaft IS'I,see Fig. 13, rotatable in a sleeve I38 in the upper bearings H5:and I3I.A mitre gear I 55 secured to the lower end of shaft I51 meshes with amitre gear I4I secured to a shaft I42'extending forwardly to thedifferential mechanism H2. Shaft I52 is supported in a bearing memberI43 which is se cured to and braces chassis members I I2 and I it, seeFig. 11. Mitre gear I50 also meshes with mitre gear I44 securedto arearwardly leading shaft I45 connected-to-diflerential mechanism I26.This shaft has abearing member I45 similar to part I43 and secured toand bracing chassis members I21 and I28. When engine I2!) is run ingpower is transmitted through the gearing and shafts just described todrive-the wheels I I5 and The two units FI and RI are joined by asupport member I55 somewhat similar to the support member of thepreferred form. This member has arms I5I at its left end, Fig. 12,formed with arcuate slots I52 and a short straight longitudinal slotI53. These slots have passing through them screws I54 and a king pin I55formed as a screw. The screws I54 and I55 are essentially the same asthose described for the preferred form of the invention and are tappedinto the bottom plate I56 of the differential mechanism I I2. The righthand end of support member I55 is similar to the left hand end and issimilarly connected to the differential mechanism I26.

Support I has a part I 50 intermediate its ends extending transverselythereof and formed with a guide slot I5 I. A gear rack I52 is secured atI63 to the underside of part I50 at one side of slot IBI. This gear rackmeshes with a pinion I64 secured to the lower end of a short verticalsteering shaft I coaxial with shaft I31 and rotatable in a sleeve orbushing I 56 fitting into and pivotally connecting the lower bearings H6and I32. Bushing I65 has a reduced lower end I51 which fits into and isguided by slot I5 I.

The upper end of shaft I55 has secured thereto a gear I68 meshing withanother gear I69 secured to the lower end of a steering post I'll). Thispost is rotatable in vertically aligned side bearings HI and I12 on mainbearings H5 and I I6, respectively, and has a steering wheel I13-securedto its upper end accessible to a driver in seat I14. The seat is shownin Fig. 11 as being mounted on the top bearing H5, but this isnot theonly way in which it can be supported.

When the modified dual tractor Tl' is moving ahead in a straight linethe shaft I65 will'befis' indicated in Fig. 12, that is, substantiallyin alignment with the king pins I55 and midway of Under these conditionspower from the engine driving shaft will be transmitted through verticalshaft I31 to the the length of slot IBI.

horizontal shafts I52'and I45 and thence to their respectivedifferential mechanisms and wheels.

If a turn is to be made to the left when traveling in the direction ofarrow b, Fig. 15, steering wheel I15 will be turned in a'directionto'move pinion I54 toward the right hand end of slot IIiI' to some suchposition as shown in Fig. 15. Since the steering shaft I55 is verticallyaligned with the power shaft I3? and the chassis members are rigid withtheir respective units the latter will be turned to the position shownin Fig. 15. If it be desired ot make a right hand turn the steeringwheel will be rotated to move the steering shaft I65 toward the oppositeend of slot IGI so that the units will be in positions suggested by dotand dash lines o and d, Fig. 15. During the turning operations thesteering wheel and seat I14'will' move transversely with the bearingsfor the nection so that both units will move the same angular amountwhen the steering mechanism moves along the guide means.

From the foregoing it will be seen that the invention sets forth a dualtractor the units of which are pivoted together about an axis alongwhich driving power is transmitted to drive at least one of the units.Steering means shifts this axis laterally to effect right or left handturning and power is transmitted to both units during the steeringoperation. In the preferred form a motor is utilized to cause lateralshifting of the pivot of the two units, whereas in the modified form thepivot is moved manually. Both forms employ an elongated support memberthe ends of which are pivotally connected to the units and the centralpart of which has means for guiding the vertical axis about which theunits are pivoted and along which driving power is transmitted. In theform shown in Fig. 11 the steering wheel and seat move laterally withthe vertical axis.

Having now particularly described and ascertained the nature of theinvention and in what manner the same is to be performed, what isclaimed is:

1. In a dual tractor, a pair of similar tractor units each having roadengaging means to be moved for propulsion purposes, a vertical sleevemember serving as a common pivot for said units, a source of power onone of said units, power transmission means supported in part by eachunit and driven by said source of power and operatively connected toeach road engaging means and including a vertical shaft supported inpart by and rotatable within said sleeve member, support means carriedjointly by said units and having a sliding pivotal connection with eachunit, and steering means including a screw screwthreaded through a partof said sleeve member and mounted on the support means and capable whenturned of moving said sleeve member and shaft at right angles withrespect to a line joining said pivotal connections to move each unitabout the sleeve member to change the angular relation of said unitsrelative to said line while said shaft is rotating.

2. The dual tractor set forth in claim 1 wherein said support means isformed with a guide slot transverse of said line along which said partof the sleeve member is movable and the axis of said sleeve memberpasses through the axis of said screw.

3. The dual tractor set forth in claim 1 wherein said shaft of the powertransmission means is coaxial with said sleeve member and has securedthereto a gear meshing with a gear on one of said units and meshing alsowith another gear on the other unit.

4. In a dual tractor, a pair of similar tractor units pivoted togetherabout a common vertical axis and each unit having road engaging means tobe moved for propulsion purposes, a source of power on one of saidunits, power transmission means supported in part by each unit anddriven by said source of power and operatively connected to each roadengaging means and including a vertical shaft rotatable about said axis,support means carried jointly by said units and having a sliding pivotalconnection with each unit, a straight rack on said support meansextending transversely of the dual tractor at right angles to a linejoining said pivotal connections, and a gear meshing with said rackcoaxial with said shaft of the transmission means and effective whenrolled along said rack to move said axis and shaft at right angles tosaid line to change the angular relation of said units about said axisand cause each unit to slide with respect to the sliding connectiontherefor on said support means to the end that both units will turnsubstantially equal angular amounts relatively to said line.

5. In a dual tractor, a pair of similar tractor units pivoted to eachother about a common vertical axis, support means extending from oneunit to the other unit and having a sliding pivotal connection with eachunit, guide means on the support means transverse thereof and at rightangles to a line joining said pivotal connections, each unit beingmovable about the pivotal connection thereof relatively to said supportmeans, steering means operatively interposed between said support meansand said units movable along said guide means to move said vertical axisat right angles to said line and move said units angularly relatively tosaid support means and slidingly with respect to their respectivepivotal connections, and power transmission means to transmit drivingpower from one of said units to the other unit through said axis for allangular positions of the units relative to said support means.

6. The dual tractor set forth in claim 5 wherein the transmission meansincludes a shaft coaxial with said axis and movable by said steeringmeans at right angles to said line and having secured thereto a gearcoaxial therewith meshing on opposite sides thereof with two gears insaid transmission means, one of said two gears being supported by oneunit and the other of said two gears being supported by the other unit.

URBAN A. MOORES.

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